As system design authority for ERTMS, ERA is responsible for the adaptation of the EU legal framework to technology evolution. As such, it is in charge of taking the necessary steps to propose this adaptation to the Member States.
It has started by organising a coordination group, which is a forum to synchronise the related initiatives taken by ETSI, UIC, Shift2Rail etc.
The possibility of offering this to the general public directly by railway companies depends on whether it is allowed in the regulation for telecommunication services.
It could be offered in partnership with public operators.
It may not necessarily be needed: the general trend for public operator obligations is to strengthen 4G coverage over rail tracks. In this case, a repeater on board could be sufficient to provide the service to the passengers.
The technologies that will be used in the future are not yet selected. It is clear that, when thinking about technologies currently available, LTE is the first one that comes to our minds. However, at the moment, there are a number of uncertainties that do not allow to get to that conclusion.
There is no evidence that LTE can support voice and data traffic when moving at high speeds (over 250 km/h) with an adequate performance. The current LTE specification does not fulfil all the railway requirements (e.g. railway emergency calls, group calls, priority and pre-emption) although the latter are planned to be included in the next LTE Releases (13 and above), to be commercially available in some years. In addition, railways are entitled to use a spectrum band that is not included in the current LTE specification and the reliability of the network has to be sufficient to cope with the RAMS requirements for railways.
A number of communication services can be made available to railways by using today’s LTE commercial networks, but this is not yet possible for the railway operational communications.
Finally, in the current EU legal framework, the use of GSM-R is mandated for railway operational communications.
There is nowadays sufficient capacity with GSM-R and GPRS for the current railway operational needs.
There is commitment from GSM-R Industry to support GSM-R at least until 2030, which will ensure the transition.
There is a risk in the technology choice (4G vs. 5G), linked to the functionality commercially available, to the expected evolution of the standards, and the availability of products. Indeed, there is no further spectrum designated for railways, other than the one currently in use by GSM-R. Furthermore, 4G standard does not include the spectrum in use by GSM-R.
A technology independent architecture model needs to be developed to ensure the split between applications (voice and data) and technology. The aim is to get to a flexible architecture, where the influence of the evolution of the radio technology is minimized.
Any new system should include GSM-R in order to protect the investments and provide continuity of railway operational communication.